Concrete floors in industrial buildings are formed, as is well known, by a plurality of slabs, each concrete slab being separated from an adjacent slab by an expansion joint. These expansion joints will permit the slabs to expand or contract without suffering any fractures due to differences in expansion rates in different portions of the concrete.
The strength of concrete floors makes them advantageous in industrial settings, such as warehouse use. Many tons of material may be stored in a warehouse without the floor suffering any damage from excessive weight. In order to efficiently handle the stored merchandise, it is necessary to use equipment which constantly rolls over the floor. The forklifts and other moving machinery will over time wear the edges of the expansion joints, thus making the expansion joint larger and the surface uneven. As the edges defining the expansion joint wear, a dangerous condition may result. Forklifts and other machinery driven over the surface of the concrete floor can be jarred, causing any cargo being transported to be dislodged and/or damaged, as well as posing a danger to the operator. Thus, from time to time such expansion joints are refinished by recutting the edges square, and filling the enlarged area with a suitable medium, such as an epoxy. The repair process envisions cutting a new expansion joint after the old worn one has been filled. The procedures used in the past for repairing concrete floors have been tedious, requiring a considerable amount of hand labor. As part of the process, part of the concrete surface must be cut away to provide a fresh square edge in the concrete. This process requires that long parallel slots be cut in the concrete surface adjacent to the old joint. The material between the slots is then broken out to form new opposing edges. The currently available apparatuses for cutting such long slots have several disadvantages.
One disadvantage is that no effective guiding is provided to permit a plurality of parallel slots to be cut accurately. By cutting accurately spaced parallel slots, it is possible to easily break away any material between the slots, thus forming an enlarged joint having the required square edges. Additionally, the refinishing of interior floors with equipment that is operated by a combustion engine releases dangerous pollutants into the air of confined spaces. Furthermore, the refinishing work is often done in an operating warehouse or other industrial facility, and only a limited work space is available, usually defined by aisles within the facility. Thus, it is important to be able to refinish the concrete joints within these aisles to as large an extent as possible, without requiring large-scale moving of stored merchandise or other materials within the facility.
The present invention has been devised to provide an economical solution for overcoming the foregoing difficulties in the repair of concrete floors.